Shoutbox

Ok, i'm trying to make some kind of spoiler tag for my blog. I can only use javascript.

I thougt I'd use a div with the class spoiler and then a link to make these classes visible or invisible.

Only problem I can't get it working

What I have now is this:
css:

code:

---

.spoiler{
  visibility:hidden;
}

---

javascript:

code:

---

function spoiler(){
      'if(document.getElementById(spoiler).style.display = 'hide'){
         document.getElementById(spoiler).style.display = 'block';
      'else{
         'document.getelementbyid(spoiler).style.display = 'hide';
      }
   }

---

html link:

code:

---

<a href="#" onClick="spoiler()">Spoilers (on/off)</a>

---

Oh, and I want it easy cause I have almost no experience with javascript

Can please somone help me?